If we’re all individuals, why do we all feel the same about this “fact”? If it is a common factor that we all think we’re unique how can we all be? In Monty Python’s “Life of Brian” the paradox is made clear!
So how do we know if it is justified to think of ourselves as unique? From a biological perspective we may have so much DNA in common with primates that we are only unique in terms of brain power. From many religious perspectives our uniqueness might have a spiritual basis. From a psychological perspective we might be individual in the sense of possessing a unique personality and innate characteristics. On the other hand there are at least six universal emotions that we share, regardless of culture or our point in history: happiness, sadness, anger, fear, disgust and surprise.
You could further investigate our knowledge of individualtity and uniqueness in the different areas of knowledge. For example what do historians, psychologists and economists claim about our individual knowledge?